When drums are to be transferred onto a pallet or the drums on the pallet are to be transferred to some other place with use of a drum carrier, the carrier 9 must be brought close to the pallet 8 so that a corner 81 of the pallet 8 will be positioned between the front wheels 91, 91 of the carrier 9 as shown in FIG. 5. Accordingly if the pallet is placed directly on the floor, the carrier requires a large space for access to the four corners of the pallet.
To overcome this problem, I have already invented a pallet rotating apparatus as shown in FIGS. 5 and 6. The apparatus is disclosed in detail in Published Unexamined Japanese Utility Model Application SHO 54-65166and Registered Japanese Design Publication No. 512417.
With reference to FIG. 6, the pallet rotating apparatus comprises an annular under ring 2 and an upper ring 6 fitting over the ring 2. The under ring 2 has a peripheral wall 22 provided with support shafts 3. The upper ring 6 is supported by bearings 4 mounted on the shafts 3. Steel balls 33 each mounted on the forward end of the support shaft 3 are opposed to the peripheral wall 62 of the upper ring 6 to prevent the lateral movement of the upper ring 6.
Since the steel ball 33 is fitted in a cavity 31 formed in the forward end of the support shaft 3 and is prevented from slipping off by a crimped peripheral edge defining the cavity 31, the ball 33 is not smoothly rollable. Further when brought into contact with the peripheral wall 62 of the upper ring 6, the steel ball 33 is forced to roll while producing great frictional resistance by contact with the inner peripheral surface defining the cavity 31 and with its bottom. Eventually, therefore, the ball 33 becomes no longer rollable due to local wear to impede the rotation of the upper ring 6.